The United States on Wednesday imposed sanctions on two Moldovan oligarchs and others over corruption or alleged collaboration with Russia to undermine the frontline country’s democracy.

The sanctions come as Western powers seek to bolster support for Moldova amid fears the war in neighboring Ukraine could spill over as Russia deploys troops in Moldova’s breakaway Transnistria region.

The United States said it blocked all US assets and criminalized transactions involving Ilan Shor, an Israeli-born businessman-turned-populist politician in Moldova, from which he fled in 2019.

Shor was married to a pop singer decorated by President Vladimir Putin and was convicted in 2014 of stealing $1 billion from Moldovan banks.

The US Treasury Department said Shor worked with Russia to forge an alliance ahead of the 2021 election and later coordinated with Moscow to soften Moldova’s efforts to join the European Union.

The Treasury also imposed sanctions on another powerful oligarch, Vladimir Plahotniuc, who fled the country in 2020 amid bribery allegations and has already been refused entry by the United States.

Secretary of State Antony Blinken said the United States “promotes accountability for systemic efforts to undermine Moldova’s democratic institutions and elections.”

“The United States will continue to hold accountable those who threaten democracy abroad,” he said in a statement.

The Ministry of Finance has also targeted seven other individuals and 12 organizations over alleged Russian attempts to interfere in Moldovan politics.